During endoscopic procedures the physician inserts a flexible endoscope manually and navigates the device by visualizing the internal path using the integrated camera. In Colonoscopy, despite the use of various pre-colonoscopy cleansing regimes, in many cases the operator's field of view is severely restricted by fecal debris and other particulate matter that is left behind in the colonic lumen or other body passage.
Various attempts have been made to provide procedures and means for washing the colonic lumen prior to performing a colonoscopic investigation. The diagnostic accuracy and the therapeutic safety of colonoscopy (as well as of other diagnostic/therapeutic procedures such as virtual colonoscopy, sigmoidoscopy, barium enemas and pill camera) depend, to a large extent, on the quality of the colonic cleansing or preparation. The ideal preparation for colonoscopy would be one that is acceptable to the patient, cleans the bowel and reliably empties the colon of all fecal material in a rapid fashion without causing damage to the colonic tissues. An ideal preparation would also minimize or eliminate any patient discomfort. Common preparations for cleansing include diet in combination with a cathartic agent, polyethylene glycol preparations, gut lavage and phosphate preparations (oral sodium phosphate and tablet form of sodium phosphate). The use of each of these techniques, however, has significant limitations.
Various attempts have been made to provide procedures and means for washing the colonic lumen during the endoscopic procedure by means of flushing water through the working channel onto the gastro-intestinal (GI) tract walls to spray the mucosa and cleanse it of areas of bleeding, fecal remains etc., and aspirating the liquids and remains through the working channel. In certain endoscopes there exists a separate small channel (e.g. 0.8 mm diameter) for irrigation, in addition to the aspiration channel. It has been found that flushing liquids through the working channel and/or the abovementioned smaller channel is not effective. Thus, when the working channel is used for this purpose, the fluids do not have sufficient force momentum to wash the debris and is only effective for cleansing minor areas of bleeding and for very soft feces. In the case of the small channel, it is possible to achieve higher liquid momentum that could, in principle, be used to cleanse fecal material, but such a procedure is not effective since it has only one point focus and would require the endoscope head to be moved in order to cleanse a larger area.
In prior art methods, aspiration has been achieved using vacuum pressure through the endoscope working channel. While this is relatively effective when aspirating liquid remains and/or extremely soft solid fecal material, it is less so when dealing with thicker and harder fecal material. It has previously been suggested that endoscopes with a larger channel (up to 6 mm) may be used, but this solution is limited since the main limitation of the aspiration, in addition to the limited aspiration channels, is the vacuum pressure force that is limited to 1 atm.
In principle, it should be possible to use the endoscope working channel both for insertion of endoscopic accessories such as: biopsy forceps, polypectomy snares, injection needle, spray catheters etc and for insufflation and suction of air that assist the insertion of the endoscope. It is further used for passage of cleansing fluid to the region of the colon immediately distal to the distal end of the endoscope and for the aspiration and removal of said fluid together with fecal debris. However, when using the working channel of the endoscope the irrigation has no momentum since only minimal resistive pressure exists and the irrigation fluid introduced has very low efficacy. One way to overcome this problem would be to use a catheter that is introduced to the working channel with a build in nozzle on the distal end of the catheter to enable efficient cleansing. However, a major drawback of such an approach is the fact that the presence of an irrigation catheter in the working channel would restrict the available volume that may be used for aspiration. Furthermore, the restriction in working channel volume would also prevent said volume being used for the passage of endoscopic tools or for insufflation and/or aspiration of air and aspiration of debris.
It is therefore a primary aim of the present invention to provide a device that permits effective and higher-pressure irrigation of a body cavity via an endoscopic working channel while still allowing for the use of the same working channel for other purposes, most particularly the aspiration of fluid and debris from said body cavity.
A further aim of the present invention is to provide a device that will permit irrigation and cleansing of the working channel of an endoscopic instrument without the removal of said instrument from the body, such that blockages of said channel by fecal material and debris may be prevented or removed.
A further aim of the present invention is to provide a device that will permit irrigation, cleansing and aspiration for additional applications such as: upper and lower GI bleeding, bronchoscopy, cystoscopy, gastrostomy trauma surgery where no preparation was available and endo-surgery preparation. It is a primary objective to irrigate and aspirate blood and clots as well as feces and remains in an effective way without blockage of the aspiration channel by clots and/or feces.
A further aim of the invention is to permit the upgrading of all endoscopic devices by integrating them together with a nozzle assembly, thereby not requiring the replacement of tools (for example biopsy forceps, snares, injection needles, and so on) during the procedure.
Further aims and objectives will be discussed as the description proceeds.